Variable speed control for phonograph turntable drive



Mgrch 18, 1958 J. P. SINGER 2,826,925

VARIABLE SPEED CONTROL FOR PHONOGRAPH TURNTABLE DRIVE Filed June 2, 1955 J 2 Sheets-Sheet l IN VENTOR. JOHN P. SINGER ayamw/w ATTORNEYS.

March 1-8, 1958 J. P. SINGER 2,826,925

VARIABLE SPEED CONTROL FOR PHONOGRAPH TURNTABLE DRIVE Filed June 2, 1955 2 Sheets-Sheet 2 INVENTOR. JOHN I? 5IN6ER A TTORNEKS.

United States Patent VARIABLE SPEED CGNTROL FOR PHONO- GRAPH TURNTABLE DRIVE John P. Singer, Waterloo, Iowa Application June 2, 1955, Serial No. 512,656

Claims. (Cl. 74-200) My invention relates to phonograph turntables and more particularly to a variable speed control means as an improvement over the turntable structures disclosed in United States Patents Numbers 2,438,265 and 2,438,266.

Phonograph turntables are usually constructed to be driven at a set speed or at several different selected speeds. Those disclosed in the two patents mentioned are described as two-speed drives though the actual production model-s carrying the Patent Numbers 2,438,265-6 and others are actually three-speed drives which is currently in popular favor. Such speeds are well known to be 33 45 and 78 R. P. Ms. and are determined by mechanical operation of a lever as disclosed in such patents.

I have found, however, that there are times when these set speeds are not wholly satisfactory and an intermediate speed or one for which the mechanism is not adapted to ,select is desirable. Such occasions, for illustration, mayoccur when music is played for certain dance routines where a speed intermediate the 45 and 78 setting is more preferable.

With these observations in mind the instant invention contemplates the adaptation of a variable speed control means applied to the turntable structure of. the above two patents identified.

A further object of my invention is to provide a variable speed control means of the above classthat is manu ally operable but which is automatically disengaged by the operation of the usual mechanism provided to change the speed of the turntable to a different speed outside the rangeof the variable control. Another object of this invention is to adapt my variable control means to the high speed range of a multiple speed phonograph turntable.

These and other objects will be apparent to those skilled in the art. 1 y

vMy invention consists in the construction, arrangements, and combination, of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fullyset forth, specifically pointed out in my claims, and illustrated in the accompanyingdrawings, in which: 'Fig. 1 is a top plan view of a phonographstructure embodying. my invention, M Fig. 2 is an enlarged perspective view of the turntable mechanism illustrating my variable control means applied thereto, and V Figs. 3-7, inclusive, are elevational views of my invention showing it in different stages of adjustment.

In describing this invention it will be understood that no invention is claimed in the operation of the turntable perse whichis disclosed in Patent 2,438,265 and Patent 2,438,266. Both patents are referred to since an examination of them will. show that Figs. 1-9 in said patents are substantially identical. Figs. 1-2 of this application are presented to show only the turntable generally in order to more fully understand the application of my variable control thereto. 'It is also deemed desirable to describe in general terms, however, the operation of the turntable as disclosed in the above patents.

A plate 10 for supporting the mechanism to be described will be mountable in any suitable case or chassis in a well known manner. The idler wheel 12 is journalled on an upright post 14 rigidly secured at its lower end to one end of a slide element 16. The other end of element 16 is slidably received in notches in a mount 18. Mount 18 is provided with a hub 20, having a cylindrical bore, and is journalled upon a relatively longer upstanding post 22 by a bearing fit to permit said mount hub 20 to be rotationally and longitudinally reciprocated on post 22. Post 22 also projects below plate 10. A helical spring means, not shown here, is compressively disposed between plate 10 and the underside of mount 18 to yieldingly urge mount 18 upwardly on post 22. An upstanding shaft 24 driven by motor 26 is mounted on plate 10 near the perimeter of idler wheel 12 and wheel 12 is rotated by engagement therewith. A turntable, not shown here, is carried by a post 28 and has a pendant flange with a cylindrical inner surface for engagement by the periphery of wheel 12. In the patents mentioned, the counterpart of my shaft 24 is provided with different diameters and means are provided for moving the idler wheel 12 into and out of engagement with these different diameters to effect changes in the speed of rotation thereof. My invention contemplates certain changes relative to shaft 24 and in the means for moving the wheel 12 as indicated and this will be better understood by further describing generally the operation as disclosed in the above patents.

A hand control lever 30 on plate 10 has an intermediate portion, not here shown, which extends through slot 32 on plate 10 and is rotatably aflixed to the lower projecting portion of post 22. Lever 30 has an arm 34 terminating in an upstanding handle 36 which extends outwardly beyond plate 10 and beyond the turntable previously referred to. Integrally formed to the portion of lever 30 which is attached to the lower portion of post 22 is the upstanding flange 38 which in my drawings is the counterpart of flange 79 of the cited patents. My invention embodies certain changes in this element but generally its function is to be moved laterally by lever 30 so that it engages a cam follower in the form of a cylindrical stem 40 which is preferably secured to and affords an extension of the idler wheel mount 18, said stem '40 affording a cam follower adapted to be cammingly moved to different lateral positions and to different levels as a result of lateral translatory movements of the camming lever flange 38. Thus by movements of lever 30 the mount 18 and idler wheel 12 can be moved upwardly and downwardly relative to the different diameter positions on shaft 24 so that engagement of wheel 12 with these different points afiords different speeds of rotation of said wheel. Lever 30 is provided with notches 42 engageable with a spring loaded catch 44 and these notches are arranged so lever 30 can be easily set to correspond to fixed points of relationship between wheel 12 and post 24 which are designated by indicia on the strip 46. In the operation of this turntable as disclosed in the patents referred to it is pointed out that wheel 12 has certain fixed speeds of rotation which can be selected by movement of lever 30 and the purpose of this invention is to disclose novel means for providing a variable speed control on the turntable disclosed.

. To accomplish this result, reference is had first to Figs. 3-7 where the changes in my flanges 38 can be easily compared with flange 79 as shown in Figs. 4 and 9 of the patents referred to. Flange 38 is so cut as to provide a diagonal slot 48 affording four substantially parallel surfaces, 50, 52, 54, and 56, formed in the upper surface of notch 48 and a lip or hump 58 in the lower edge thereof at a point between the lateral spacing of surfaces 52 and 54. Surfaces 50, 52, 54, and 56 are interconnected by the diagonal upper edge 57 of notch 48. Thus formed it will be understood that slot 48 provides a cam action against stem 40 as flange 38 is moved laterally by lever 30 and while this action is disclosed in the other patents I am able to achieve a different result as will appear. Another change I. have made is in the provision of pulley 60 mounted to shaft 24 which has a tapered portion 62 intermediate the portions 64 and 66 which are of fixed diameters. Using the shaft 24 to provide a rotation of wheel 12 at 33 R. P. Ms., portion 66 is set for 45 R. P. M.s. and portion 64 for 78, thus allowing surface 62 to permit a variable speed control between the 78 and 45 R. P. M. settings. faces 50, 54, and 56 in the notch 48 provide the three set position for the respective speeds of wheel 12 of 78, 45, and 33 R. P. Ms., and surface 52 provides the new position which I have called the 78 variable. It will be noted in Figs. 3-7 that notch 48 is so formed that no part of flange 38 is directly below surface 52 so that stem 40 is capable of a substantially vertical adjustment. This is possible since stem 40 is attached to mount 18 which is normally urged upwardly on post 22 by a helical spring as previously disclosed. Consequently with lever 30 set at the 78 variable position, stem 40 would normally engage surface 52 which as shown in Fig. 7 causes the periphery of wheel 12 to engage the upper diameter of tapered pulley portion 62 for the slowest speed in the variable range. In order to move wheel 12 to the dotted line in Fig. 7 or any point in between, reference is made to Figs. 1 and 2 where I show my variable control member 68.

Control 68 consists of an elongated lever 70 which is preferably designed with a step or jog 72 to carry it under the platform on which plate is mounted and a handle means 74 on its outer end for manual manipulation. Lever 70 is pivotally mounted to a bracket 76 on plate 10 so that it. extends from its pivot point toward flange 38 where an angularly disposed finger 78 is positioned to engage the top side of stem 40. Lever 70 is yieldingly held against pivoting by a spring means 80 which is tightened sufficiently only to overcome the helical spring that tends to urge mount 18 and stem 40 upwardly. Thus, with lever at the 78 variable position, lever 70 can be rocked on its pivot point by moving handle 74 upwardly or downwardly as indicated on a suitably placed instruction plate 81, which will correspondingly change the vertical position of stem and likewise change the points of contact on pulley 62 by wheel 12. It will thus be appreciated that a considerable variation in speed of wheel 12 is provided.

When it is desired to change the speed of wheel 12 to a slower one, lever 30 is moved in its normal manner and as flange 38 moves laterally the hump 58 on the lower edge of slot 48 will provide sufficient action on stem 40 to overcome spring 80so that speeds of 4S and 33 R. P. Ms. can be obtained without manually elevating finger 78.

As illustrated in Figs. 3-7, Fig. 3 shows stem 40 and wheel 12 in off position, Fig. 4 in the 78 position, Fig. 5 in the position, and Fig. 6 in the 33 speed position. Fig. 7, as described, illustrates the 78 variable setting and due to the range of speed at this setting it is pointed out that the normal or set 78 R. P. M. position could well be eliminated without in any way affecting the speedsobtainable for wheel 12.

It is submitted that the invention shown and described is aptly suited to achieve the purposes intended and is characterized by a combination of highly useful and mutually cooperating elements that combine their respective and proportionate functions in accomplishing the objects sought to be obtained.

Some changes may be made in the construction and arrangement of my variable speed control for phonograph The surturntable drive without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim:

1. In a multiple speed adjustment mechanism for phonograph turntables of the class having an upright motor driven shaft provided with axially aligned steps of different diameters, an idler wheel in peripheral engagement with said shaft, a movable mount for said idler wheel, means yieldingly biasing said idler wheel vertically toward the plane of the smaller step, a cam element adapted to be moved laterally in a continuous uniform path, a projection on said mount disposed in the path of movement of said cam element whereby communication of motion from the movement of the cam element is transferred to said idler wheel to effect vertical and horizontal moving efforts on said wheel to engage the periphery thereof at times with different diameters on said shaft, the combination therewith of a variable speed control means for said idler wheel, comprising, a pulley on said shaft having a surface of varying diameter, said cam element formed with a notch to allow vertical movement of said projection when the periphery of said idler wheel is in engagement with said pulley, a lever member yieldingly engaged with said projection, and means for manually moving said lever to respectively raise and lower said projection to selectively engage the periphery of said idler wheel at different points on said pulley.

2. In a multiple speed adjustment mechanism for phonograph turntables of the class having an upright motor driven shaft provided with axially aligned stops of different diameters, an idler wheel in peripheral engagement with said shaft, a movable mount for said idler wheel, means yieldingly biasing said idler wheel vertically toward the plane of the smaller step, a cam element adapted to be moved laterally in a contiuous uniform path, a projection on said mount disposed in the path of movement of said cam element whereby communication of motion from the movement of the cam element is transferred to said idler wheel to effect vertical and horizontal moving efforts on said wheel to engage the periph cry thereof at times with different diameters on said shaft, the combination therewith of a variable speed control means for said idler wheel, comprising, said shaft provided with a tapered portion of varying diameter intermediate two of said steps, said cam element formed with a notch to allow vertical movement of said projection when the periphery of said idler wheel is in engagement with said tapered portion, a lever member yieldingly engaged with said projection, and means for manually moving said lever to respectively raise and lower said projection to selectively engage the periphery of said idler wheel at different points on said tapered portion.

3. In a multiple speed adjustment mechanism for phonograph turntables of the class having an upright motor driven shaft provided with axially aligned steps of different diameters, an idler wheel in peripheral engagement with said shaft, a movable mount for said idler wheel, means yieldingly biasing said idler wheel vertically toward the plane of the smaller step, a cam element adapted to be moved laterally in a continuous uniform path, a projection on said mount disposed in the path of movement of said cam element whereby communication of motion from the movement of the cam element is transferred to said idler wheel, to effect vertical and horizontal moving efforts on said wheel to engage the periphery thereof at times with different diameters on said shaft, the combination therewith of a variable speed control means for said idler wheel, comprising, said shaft provided with a tapered portion of varying diameter intermediate two of said steps, said cam element provided with a substantially inclined cam surface having an intermediate portion and substantially parallel end portions, said projection adapted to traverse said. cam surface to be positionable at timesin engagement with said respective end portions, each of said end portions corresponding to apredetermined position of said idler wheel relative to its peripheral engagement with said shaft, said cam surface so formed that said projection is capable of vertical movement when said idler wheel is frictionally engaged with said tapered portion, and manual means for effecting vertical movement of said projection.

4. In a multiple speed adjustment mechanism for phonograph turntables of the class having an upright motor driven shaft provided with axially aligned steps of different diameters, an idler wheel in peripheral engagement with said shaft, a movable mount for said idler wheel, means yieldingly biasing said idler wheel vertically toward the plane of the smaller step, a cam element adapted to be moved laterally in a continuous uniform path, a projection on said mount disposed in the path of movement of said cam element whereby communication of motion from the movement of the cam element is transferred to said idler wheel to effect vertical and horizontal moving efforts on said wheel to engage the periphery thereof at times with different diameters on said shaft, the combination therewith of a variable speed control means for said idler wheel, comprising, a pulley on said shaft having a surface of varying diameter, said cam element formed with a notch to allow vertical movement of said projection when the periphery of said idler wheel is in engagement with said pulley, and manual means for effecting vertical movement of said projection.

5. In a multiple speed adjustment mechanism for phonograph turntables of the class having an upright motor driven shaft provided with axially aligned steps of different diameters, an idler wheel in peripheral engagement with said shaft, a movable mount for said idler wheel, means yieldingly biasing said idler wheel vertically toward the plane of the smaller step, a cam element adapted to be moved laterally in a continuous uniform path, a projection on said mount disposed in the path of movement of said cam element whereby communication of motion from the movement of the cam element is trans ferred to said idler wheel to effect vertical and horizontal moving efforts on said wheel to engage the periphery thereof at times with different diameters on said shaft, the combination therewith of a variable speed control means for said idler wheel, comprising, said shaft provided with a tapered portion of varying diameter intermediate two of said steps, said cam element provided with a substantially inclined cam surface having an intermediate portion and substantially parallel end portions, said projection adapted to traverse said cam surface to be positionable at times in engagement with said respective end portions, each of said end portions corresponding to a predetermined position of said idler wheel relative to its peripheral engagement with said shaft, said cam surface so formed that said projection is capable of vertical movement when said idler wheel is frictionally engaged with said tapered portion, and a manually operated rockably mounted lever engageable with said projection for effecting a vertical movement thereof.

6. In a multiple speed adjustment mechanism for phonograph turntables of the class having an upright motor driven shaft provided with axially aligned steps of different diameters, an idler wheel in peripheral engagement with said shaft, a movable mount for said idler wheel, means yieldingly biasing said idler wheel vertically toward the plane of the smaller step, a cam element adapted to be moved laterally in a continuous uniform path, a projection on said mount disposed in the path of move ment of said cam element whereby communication of motion from the movement of the cam element is transferred to said idler wheel to effect vertical and horizontal moving efforts on said wheel to engage the periphery were? thereof at times with different diameters on said shaft, the combination therewith of a variable speed control means for said idler wheel, comprising, said shaft provided with a taperedportion of varying diameter intermediate two of said steps, said cam element provided with a substantially inclined cam surface having an intermediate portion and substantially parallel end portions, said projection adapted to traverse said cam surface to be positionable at times in engagement with said respective end portions, each of said end portions corresponding to a predetermined position of said idler wheel relative to its peripheral engagement with said shaft, said cam surface so formed that said projection is capable of vertical movement when said idler wheel is frictionally engaged with said tapered portion, a manually operated rockably mounted lever engageable with said projection for effecting a vertical movement thereof, and means formed on said cam surface engageable by said projection when traversing the same to an end position outside the range of said tapered shaft portion whereby said projection overcomes the contact of said manually operated lever.

7. In a multiple speed adjustment mechanism for phonograph turntables of the class having an upright motor driven shaft provided with axially aligned steps of different diameters, an idler wheel in peripheral engagement with said shaft, a movable mount for said idler wheel, means yieldingly biasing said idler wheel vertically toward the plane of the smaller step, a cam element adapted to be moved laterally in a continuous uniform path, a projection on said mount disposed in the path of movement of said cam element whereby communication of motion from the movement of the cam element is transferred to said idler wheel to efiect vertical and horizontal moving efforts on said wheel to engage the periphery thereof at times with different diameters on said shaft, the combination therewith of a variable speed control means for said idler wheel, comprising, said shaft provided with a tapered portion of progressively increasing diameter from top to bottom below said steps, said cam element provided with an inclined cam surface having spaced parallel portions, said projection adapted to traverse said cam surface to be positionable at times in engagement with said respective end portions, each of said end portions corresponding to a predetermined position of said idler wheel relative to its peripheral engagement with said shaft, said cam surface so formed that said projection is capable of vertical movement when said idler wheel is frictionally engaged with said tapered portion, and means for effecting vertical movement of said projection.

8. In a multiple speed adjustment mechanism forphonograph turntables of the class having an upright motor driven shaft, an idler wheel in peripheral engagement with said shaft, and a movable mount for said idler wheel, the combination therewith of a variable speed control means for said idler wheel, comprising, a pulley on said shaft having a surface of varying diameter, a cam elementadapted to be moved laterally in a continuous uniform path, a projection on said mount disposed in the path of movement of said cam element whereby communication of motion from the movement of the cam element is transferred to said idler wheel to effect vertical and horizontal moving efforts on said wheel to engage the periphery thereof at times with different diameters on said pulley, said cam element formed with a notch to allow vertical movement of said projection when the periphery of said idler wheel is in engagement with said pulley, and manual means for effecting vertical movement of said projection.

9. In a multiple speed adjustment mechanism for phonograph turntables of the class having an upright m0- tor driven shaft, an idler wheel in peripheral engagement with shaft shaft, and a movable mount for said idler wheel, the combination therewith of a variable speed control means for said idler wheel, comprising, a pulley on 7 said shaft having a surface of varying diameter, a cam element adapted to be moved laterally' in 'a continuous uniform path, a projection on said mount disposed in the path of movement of said cam element whereby communication of motion from the movement of the cam element is transferred to said idler wheel to eflect vertical and horizontal moving efforts on said wheel to engage the periphery thereof at times with different diameters on said pulley, said cam element formed with a notch to allow vertical movement of said projection when the periphery of said idler wheel is in engagement with said pulley, means yieldably biasing said idler Wheel vertically in one direction, and manual means engageable with said projection to move said idler wheel vertically in the other direction.

10. A device as defined in claim 9 in which the manual means includes a spring mounted rockable lever adapted ,to maintain said projection at any selected position Within said notch.

References Cited in the file of this patent UNITED STATES PATENTS 2,438,265 Metzner Mar. 23, 1948 2,577,649 Dale Dec. 4, 1951 2,584,580 Hardy 2 Feb. 5, 1952 

